On the Coupling of Local Discontinuous Galerkin and Conforming Finite Element Methods

The finite element formulation resulting from coupling the local discontinuous Galerkin method with a standard conforming finite element method for elliptic problems is analyzed. The transmission conditions across the interface separating the subdomains where the different formulations are applied are taken into account by a suitable definition of the so-called numerical fluxes. An error analysis leading to optimal a priori error estimates is presented for arbitrary meshes with possible hanging nodes. Numerical experiments validating the theoretical results are reported.     

基于PCA优化的PSO-FCM聚类算法

为解决PSO-FCM聚类算法针对多聚类问题,性能不足,容易陷入局部最优解,影响多聚类结果的准确度.提出一种基于PCA优化的PSO-FCM聚类算法,通过引入PCA分析方法,在粒子的各维度上设定不同的移动权重,降低粒子的敏感度,合理的控制粒子各维度上移动的速度,有效的降低粒子各维度上粒子无约束,位于多个聚类群交界处的粒子过分敏感,移动到错误的聚类的可能性增加.本文简要介绍了PSO-FCM算法的相关情况,详细介绍了本文的优化算法,最后通过实验证明,本文提出的优化算法在多个数据集上结果总体优于其他算法.     

Estimation of wave responses from subvertical macrofracture systems using a grid characteristic method

This work investigates the formation and propagation of scattered waves forming a response of crack structures on the seismologic record. The initial impulse is a flat wave front propagating into the depth of the medium. The paper considers the periodic structure of the scattered wave response from a system (cluster) of subvertical cracks. The procedures of estimation of geometrical parameters of such crack structures are based on numerical experiments. We use a grid-characteristic method to calculate the triangular grids with the formulation of boundary conditions at the interface of the medium and the cracks, as well as on the borders of the region of integration with the characteristic properties of the governing equations of the hyperbolic type. This numerical method makes it possible to build the most correct numerical algorithms on the boundaries of the integration domain and on the surfaces of the media division (interfaces) and to take into account the domain of the solution’s dependence and the physics of the problem (propagation of disturbances on the characteristic directions). This is why this method is perhaps the most suitable one for the numerical solution of dynamic problems with a distinct wave character in geologically substantially inhomogeneous media, in particular, for the considered problem of seismic waves interaction with fissured structures.     

优化的互信息特征选择方法

在文本分类中,互信息是一种被广泛应用的特征选择方法,但是该方法仅考虑了特征的文档频而没有考虑特征的词频,导致它经常倾向于选择出现频率较低的特征。为此,提出了一个新的文档频并把它引入到互信息方法中,从而获得了一种优化的互信息方法。该优化的互信息方法不但考虑了特征的文档频而且还考虑了特征出现的词频。实验结果表明该优化的互信息方法性能良好。     

Investigation in the interface adhesion strength between SU-8 photoresist and metal substrate by ultrasonic treatment

During the fabrication process of metal microstructures and microdevices by ultraviolet Lithographie Galvanoformung Abformung technology of SU-8, it is common for interface separation and bind failure due to the poor adhesion strength between SU-8 photoresist and metal substrate. In this paper, ultrasonic wave was introduced into the lithography process to improve the interface adhesion strength. Scratch test method was adopted to measure the interface adhesion strengths between SU-8 photoresist and metal substrate without ultrasonic treatment and with ultrasonic treatment under different ultrasonic conditions. The effects and corresponding mechanisms of ultrasonic time and ultrasonic power on the interface adhesion strength between SU-8 photoresist and metal substrate were investigated. The results showed that due to the input of the ultrasonic vibration, the crosslink network characteristics of SU-8 photoresist were changed. The internal stress in SU-8 photoresist was reduced and the interface adhesion strength was improved. The interface adhesion strength firstly increased and then decreased with the increase of ultrasonic time. The maximum interface adhesion work was 0.427 J/m² at an optimized ultrasonic time of 10 min, which was higher than that of the sample without ultrasonic treatment by 39.5 %. Besides, in the experimental conditions, the interface adhesion strength first increased and then decreased with the increase of the ultrasonic power and the maximum interface adhesion strength attained at the ultrasonic power of 352 W. The ultrasonic treatment method can effectively improve the interface adhesion strength, so as to increase the product yield and performance.     

A new model for slab and beam structures––comparison with other models

In this paper an optimized model for the analysis of plates reinforced with beams is presented as compared with other models used by various researchers. The adopted model contrary to the models used previously takes into account the resulting inplane forces and deformations of the plate as well as the axial forces and deformations of the beams, due to combined response of the system. According to this model the stiffening beams of the structure are isolated from the plate by sections parallel to the lower outer surface of the plate. The forces at the interface, which produce lateral deflection and inplane deformation to the plate and lateral deflection and axial deformation to the beam, are established using continuity conditions at the interface. The adopted model describes better the actual response of the plate-beams system and permits the evaluation of the shear forces at the interface, the knowledge of which is very important in the design of composite or prefabricated ribbed plates. Four additional models neglecting the shear forces at the interfaces are presented and used for comparison reasons, while a three-dimensional elasticity model is also employed for the verification of the accuracy of the results of the examined models. The findings from this investigation, using the adopted model, which approximates better the actual response of the plate-beams system, necessitate the consideration of the inplane forces and deformations.     

A high-order compact scheme for the one-dimensional Helmholtz equation with a discontinuous coefficient

In this paper, based on the idea of the immersed interface method, a fourth-order compact finite difference scheme is proposed for solving one-dimensional Helmholtz equation with discontinuous coefficient, jump conditions are given at the interface. The Dirichlet boundary condition and the Neumann boundary condition are considered. The Neumann boundary condition is treated with a fourth-order scheme. Numerical experiments are included to confirm the accuracy and efficiency of the proposed method.     

An I/O Automata-based Approach to Verify Component Compatibility: Application to the CyCab Car

An interesting formal approach to specify component interfaces is interface automata based approach, which is proposed by L. Alfaro and T. Henzinger. These formalisms have the ability to model both the input and output requirements of components system. In this paper, we propose a method to enrich interface automata by the semantics of actions in order to verify components interoperability at the levels of signatures, semantics, and protocol interactions of actions. These interfaces consist of a set of required and offered actions specified by Pre and Post conditions. The verification of the compatibility between interface automata reuse the L. Alfaro and T. Henzinger proposed algorithm and adapt it by taking into account the action semantics. Our approach is illustrated by a case study of the vehicle CyCab.     

基于概念间双向语义和多重关系的Web服务发现

如何提高Web服务的发现效果是面向服务计算领域需要解决的关键问题.针对这一问题,文中提出基于概念间双向语义和多重关系的Web服务发现方法.在计算概念相似度时,考虑语义的双向性及连接路径上的多重关系.不同于以往的服务发现方法,不仅计算服务描述中的名词和动词,还计算形容词.在名词和动词相似度计算中,涵盖继承关系(ISA)、部分整体关系(HASA)和反义关系(ANT).在形容词相似度计算中,涉及相似关系(Similar-to)和ANT.Web服务相似度的计算综合I/O和功能描述两方面内容,提高Web服务发现的准确性.通过综合数据实验充分验证文中方法的有效性,该方法具有较优的查准率、查全率及F-measure.     

基于N-Gram的Deep Web接口属性抽取

Deep Web中,查询接口属性的抽取是Deep Web数据集成中必不可少的一个环节。本文通过将接口属性中文文本翻译成为汉语拼音和英文,利用N-Gram方法完成中文查询接口中属性的抽取。经过多个领域的查询接口的实验,证明该方法能有效地抽取出查询接口的属性。     

Identification of a rice drying model with an improved sequential optimal design of experiments

Getting relevant parameter estimation of a non-linear model is often a hard task from both an experimental and numerical point of view. The objective of optimally designed experiments procedure is to diminish the experimental effort needed such that the identification is within acceptable confidence ranges. After each experiment, the next experiment is optimally designed, taking into account all past experimental results. It allows quality information to be extracted from the experimental data with less experimental time and resource consumption.In this paper, we present an original approach and implementation of the classical A-, D- and E-optimality on the estimation of 5 unknown (transfer related) coefficients in a compartmental model used to describe the convective drying of rice. The originality of our method is that it uses reparameterization of both parameter and protocol vectors which permits to avoid using a global optimization algorithm. The presented method is implemented in Matlab as a Toolbox and fully tested on a pilot plant. The case study (drying of rice) is typical in the field of process engineering: the dynamic model is strongly non-linear in its parameters and cannot be analytically solved. In addition, the specific technical constrains (inertias, limits, etc.) on the pilot are explicitly taken into account for improved experimental feasibility.In this drying application, three experiments with non-constant drying conditions are shown to be quite as effective as a two-factor three-level grid of nine experiments at constant conditions, with only one third of the experimental effort.     

OptiFuzz: a robust illumination invariant face recognition system and its implementation

Vision-based human face detection and recognition are widely used and have been shown to be effective in normal illumination conditions. Under severe illumination conditions, however, it is very challenging. In this paper, we address the effect of illumination on the face detection and the face recognition problem by introducing a novel illumination invariant method, called OptiFuzz. It is an optimized fuzzy-based illumination invariant method to solve the effect of illumination for photometric-based human face recognition. The rule of the Fuzzy Inference System is optimized by using a genetic algorithm. The Fuzzy’s output controls an illumination invariant model that is extended from Land’s reflectance model. We test our method by using Yale B Extended and CAS-PEAL face databases to represent the offline experiments, and several videos are recorded at our campus to represent the online indoor and outdoor experiments. Viola–Jones face detector and mutual subspace method are employed to handle the online face detection and face recognition experiments. Based on the experimental results, we can show that our algorithm outperforms the existing and the state-of-the-art methods in recognizing a specific person under variable lighting conditions with a significantly improved computation time. Other than that, using illumination invariant images is also effective in improving the face detection performance.     

Designing the user interface using rapid prototyping

The aim of this study was to evaluate and improve the menu interface design of an existing expert system. The system provided expertise concerned with evaluating human response to environments and was implemented onto a computer with a simple tree menu system. Two laboratory based experiments were carried out in which alternative menu interface designs were developed rapidly and compared with the original design. User acceptance tests which incorporated objective and subjective measures were iteratively used to evaluate and improve the interface designs. The results of these experiments indicated that, for the particular system under study, a graphic based design which displayed 58 options divided into levels on a single screen was preferred by users over the original menu interface which displayed one menu at a time with seven options per screen. The final interface remains to be tested under field conditions.     

融合认知负荷的用户界面布局优化

为了优化项目管理系统界面, 提升界面的可用性, 提出一种融合认知负荷的界面布局优化设计方法. 该方法将客观认知规律与用户主观认知相结合, 形成布局设计原则, 并转化为可计算的界面布局多目标优化函数. 在此基础上, 利用麻雀搜索算法对目标函数编码, 寻求空间最优解, 得到布局优化方案. 为验证本文方法的有效性, 以某铁路项目管理平台首页为例, 使用该方法对其进行优化, 并将眼动生理测量方法引入评价过程中, 以测量眼动负荷大小为目标进行可用性测试. 实验结果表明优化后的界面布局相较于初始界面可用性指标有了明显提升, 证明了该方法的有效性且具有一定的实用性.     

Mathematical modeling and numerical simulation of freezing processes of a supercooled melt under consideration of density changes

In this paper, we derive a model for the two-phase freezing process of supercooled fluids. Especially, we take density changes along the phase interfaces into account. Thus, besides heat diffusion and the interface phenomena, mass transport and convection in the fluid phase which is given by the full Navier–Stokes equations has to be considered. For the 2D case we implemented an algorithm for the numerical solution of the mathematical model using uniform volume cells for a finite difference discretization. Additionally, the phase boundaries are captured by a surface tracking method. We report on the mathematical model and its derivation, describe the numerical algorithm and present numerical experiments. Received: 11 September 1997 / Accepted: 19 June 1998     

性别鉴别的线性可分性分析

首次从线性可分性的角度探讨了人脸图像的性别鉴别问题。通过对常用线性与非线性特征抽取方法以及一类改进的非线性特征抽取方法的对比分析及不同情况下性别鉴别的实验对比,较全面地考察了各种特征抽取方法所对应的数据的线性可分性及分类效果。首次提出从人脸肤色等角度考虑人脸图像的性别鉴别问题,并给出了指示意义较强的鉴别方法与方案建议。     

Influence of micro-cracking and contact on the effective properties of composite materials

In the present work a novel micro-mechanical approach to analyze the influence of micro-crack evolution and contact on the effective properties of elastic composite materials is proposed, based on homogenization techniques, interface models and fracture mechanics concepts. By means of the finite element method, enhanced non-linear macroscopic constitutive laws are developed by taking into account changes in micro-structural configuration associated with the growth of micro-cracks and with contact between crack faces. Numerical simulations are carried out for the cases of a porous composite with edge cracks and of a debonded fibre reinforced composite, loaded along extension/compression uniaxial macro-strain paths. Micro-crack propagation is modelled by using an original methodology based on the J-integral technique in conjunction with an interface model taking into account the unilateral contact of crack faces. In the context of a micro-to-macro transition obtained by controlling the macro-deformation of the micro-structure, the effects of adopting three types of boundary conditions on the macroscopic constitutive law, namely linear deformation, uniform tractions and periodic deformations and anti-periodic tractions, are studied. As a consequence, the proposed method can be applied to a large class of problems including periodic, locally periodic and irregular composite materials. Micro-crack and contact evolution result in a progressive loss of stiffness and can lead to failure for homogeneous macro-deformations associated with unstable crack propagation.     

主体接口技术研究及其Java实现

结合软件BDL主体的工作原理，对主体的接口技术进行了研究，并使用Java语言给出程序实现。通过提供的接口，用户可以指示主体去完成特定工作，对主体资源进行存取和影响主体的行为模式。     

基于遗传优化谱聚类的图形分割方法

传统的谱聚类方法使用k-means达到最后的聚类目的。k-means对初始条件敏感,易陷入局部最优,从而导致传统的谱聚类方法应用到图像分割时效果不太理想。将遗传算法用于优化谱方法的聚类阶段,提出一种以遗传算法优化普聚类的图像分割方法(Image Segmentation Algorithm of Spectral Clustering Optimization Based on Genetic,ISCOG)。在合成图像与真实图像上的实验表明ISCOG算法极大地提高了谱聚类算法的稳定性和聚类质量,证明了ISCOG算法的优越性。